@inbook{NBERc2521,
 Crossref = "NBERwill59-1",
 title = "Appendix C: Basic Series on Soviet Transportation",
 author = "Ernest W. Williams, Jr.",
 BookTitle = "Freight Transportation in the Soviet Union: A Comparison with the United States",
 Publisher = "Princeton University Press",
 pages = "169-208",
 year = "1959",
 URL = "http://www.nber.org/chapters/c2521",
}
@book{NBERwill59-1,
 title = "Freight Transportation in the Soviet Union: A Comparison with the United States",
 author = "Ernest W. Williams, Jr.",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "Princeton University Press",
 year = "1959",
 URL = "http://www.nber.org/books/will59-1",
}